This invention relates to a method and apparatus for thoroughly mixing ethanol and air in the right proportion for efficient combustion inside the engine's combustion chamber utilizing evaporator and the suction pressure of the intake manifold of said engine.
In the present utilization of ethanol as a fuel, either alone or blended with gasoline, anhydrous ethanol (100% purity) is required. The production of anhydrous ethanol using conventional technology is difficult and expensive due to its azeotropic property wherein at 95% purity, water and ethanol evaporate and distill in the same proportion, thereby requiring special processes and equipment. The present use of ethanol gasoline blends introduces operating difficulties especially in starting, accelerating, and vapor lock. Likewise, the use of regular ethanol using existing gasoline carburetor suffers from the same difficulties. The ethanol or ethanol-gasoline blend is inducted in an atomized state by the rush of intake air into the engine carburetor and through the intake manifold wherein the air-fuel mixture may not be thoroughly in its vaporized flammable state, still containing droplets of gasoline, water, and ethanol, thereby resulting in an incomplete combustion of the fuel with smoke and carbon deposit and the corrosive effect of water.
The method and apparatus of this invention contemplates of thoroughly mixing ethanol and air in the right proportion for efficient combustion in the engine. The air is aspirated by the vacuum developed by the piston displacement of the engine in the intake stroke and is bubbled into the ethanol thereby evaporating the ethanol and thoroughly mixing them in a homogeneous air-fuel flammable mixture and introducing it into the engine intake manifold free of any water moisture and any liquid fuel droplets. Ethanol has a unique azeotropic property wherein its affinity with water is greatly reduced as pressure is reduced. Consequently, when a vacuum is created over a container of ethanol, ethanol vaporizes more readily leaving behind the water initially in solution with it. Because when ethanol vaporizes, it needs about 370 BTU of heat per pound which heat is partly taken from the water in solution greatly reducing its temperature thereby suppressing its vaporization. At the same time, the air is also filtered of solid impurities as it is bubbled into the ethanol. Water moisture in air is condensed as a consequence of the low temperature (about 50.degree. F.) of the liquid ethanol and water in solution. The combustion of the ethanol using this method is perfect without any unburned fuel residue (carbon soot).
The device using this method will be much simpler in design and fewer parts and controls for the need of a venturi to induct the fuel may be eliminated. The possibility of flooding the engine is also eliminated. This method and device will separate any water contamination of the ethanol due to the fact that ethanol is more volatile than water and in the process of vaporization it will in effect suppress the vaporization of water present and in fact, will condense any water vapor present in the air. As a consequence, the thermal efficiency is improved significantly.